Here you go!

There are 3 variations of same formula. In 2nd one I replaced subformulas of 1st one with dynamic Names, to make the formula on sheet more readable. The 3rd one is copy of 1st one, but it uses dynamic Named Ranges as source instead on Table (it's for case you don't want to use defined Tables).

You can replace month number in current format with date of 1st of month, and format it then in any way too. But remember, the values you use for months must grow in right order! (I.e. texts like "January 2020" and "February 2020" will not do.)

Attached Files

LastEntryCalc.xlsx (10.6 KB, 11 views)